Farms cover nearly half the land in Wisconsin, creating an immense stress on the natural biodiversity of the state’s landscape.

But farms can also drastically increase the diversity of plants, birds and beneficial insects by incorporating uncultivated land, University of Wisconsin-Madison scientists reported this week at the Ecological Society of America’s annual meeting in Milwaukee.

The researchers showed that non-cropland adjacent to potato fields in central Wisconsin harbors a significant proportion of the state’s original pre-agricultural biodiversity, even without ecological management. Active restoration schemes further enhanced the natural ecosystem, the researchers found.

The UW team is working with the Wisconsin Potato & Vegetable Growers Association, the U.S. Department of Agriculture, the World Wildlife Fund and other conservation groups to implement a Wisconsin “Healthy Grown” potato label.

The label aims to create an economic incentive for growers to implement conservation plans that support broad ecosystem health. It’s not organic, as pesticides are still used, but it does let consumers know that producers grow foods following specific environmental standards.

“We’ve got to address how we can best preserve the biodiversity of these mixed agriculture landscapes,” said UW environmental studies professor Paul Zedler, who led the research into the label’s ecological impact. “So, the first thing we did was figure out what’s out there.”

In the designated fallow lands next to six of the 11 “Healthy Grown” potato farms in Adams and Portage counties, UW botanist Leith Nye found 276 plant species, over 200 of which were native to Wisconsin.

“There’s a significant reservoir of native plant diversity in this landscape,” Nye announced Thursday.

The uncultivated border regions on farms also provide a refuge for helpful beetle species that eat the seeds of undesirable weedy plants, UW entomologist Hannah Gaines reported Thursday.

“The abundance of the seed eaters was much higher in the non- crop habitat than in the croplands,” she said.

Although the uncultivated lands increased insect biodiversity, the beneficial beetles didn’t seem to move into cropland. Gaines said, however, that different field layouts that incorporated “beetle bank strips” stretching into the potato fields should facilitate insect-based weed-killing for crops.

The field margins provide protection though from the Colorado potato beetle, a key potato pest that has developed resistance to many pesticides.

The UW scientists plan to continue to work together with potato farmers to expand the “Healthy Grown” labeling project.

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